Staging: comedi: drivers: fix space coding style in am9513.h

This is a patch to the file am9513.h that fixes missing space warnings
found by the checkpatch.pl tool.

Signed-off-by: Bob Beattie <bob.beattie@ntlworld.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>